Figure 2: Two GPR profiles from the 200 and 40 MHz surveys.
From: Ice stream motion facilitated by a shallow-deforming and accreting bed
Details are enlarged and coloured in correspondence to the auger samplings (WP) and, in two cases, further enlargements show the strongest reflectors identified within each profile. In a, the only significant reflector besides the surface waves is found at a variable depth of 0.3–0.5 m, and augering and trench observations confirm this to be the boundary between the organic soil and the diamicton below. In b, the only significant reflector is verified at a depth of 1.8–2.6 m and augering confirms this to correspond to the water table/capillarity fringe system within the diamicton. All other reflectors, parallel to the surface or the water table, are interpreted as multiples.
